This invention relates generally to non-stick, durable performance coatings for use on equipment components, particularly including coatings for use in the semiconductor industry.
The semiconductor industry uses equipment known as Chemical Mechanical Polishing (CMP) equipment in the manufacture of wafers. CMP equipment flattens the silicon or other wafer surface to within 50-nanometer precision or better. CMP flattens the wafer by removing material from the uneven wafer surface until a flat, or xe2x80x9cplanarizedxe2x80x9d surface is created. By flattening the surface, photolithography can take place with greater accuracy, enabling film layers to be built up with minimal height variations. CMP is both a chemical and mechanical process, combining an acidic or basic fluid solution with an abrasive polishing material. The CMP system usually has a polishing head that presses the rotating wafer against a flexible pad. A wet chemical slurry containing a micro-abrasive is placed between the wafer and pad.
CMP is especially critical to fabricating copper-based semiconductors, where it is used to define the copper wiring structures. This advanced smoothing capability enables chipmakers to continue shrinking circuits and extends the performance of lithographic tools. Accordingly, CMP is an important part of the semiconductor chip-making process.
Unfortunately, the chemicals used in this smoothing process attack and degrade the CMP equipment and all related components. As a result, the CMP equipment wears out rapidly and must be replaced or refurbished frequently. In addition, the coating on the tooling degrades and sheds particulates, introducing foreign matter and hindering the process of smoothing the wafers.
The industry presently relies exclusively on anodized aluminum and standard powder coating to protect the CMP equipment and to reduce particle contamination. While anodized aluminum is better than uncoated metals or certain other materials, it still suffers from degradation and particle contamination
Accordingly, there is a need to provide better protection for tooling against the damaging effects from the slurry used in the industry. Aside from the CMP uses, there is a general need for improved coatings for equipment parts that are used in an environment of wear or foreign matter build-up.
The present invention provides a wear indicating coating for a variety of tools or other components, particularly including Chemical Mechanical Polishing equipment having a working surface configured to planarize a semiconductor material surface. The wear indicating coating includes a fluoropolymer based primer coating adjacent the working surface. Adjacent the primer coating is a fluoropolymer based coating. The coating may contain a pigment or colorant to visually contrast the coating from the particulates or foreign matter that may be deposited on the CMP equipment. Thus, the pigment allows CMP equipment users to see equipment wear and particle build-up as indicated by slurry build-up at early stages.
The present invention further includes a unique method of forming a mechanical and chemical resistant coating upon a substrate, which, in the case of CMP parts, is typically a metallic substrate. The method starts by masking the areas of the substrate that are not to be coated. Subsequently, the surface to be coated is prepared by roughing the surface to improve the surface""s bonding characteristics. The next step is preheating the substrate to a predetermined temperature followed by applying a primer coating. After applying the primer coating to the substrate, another heating step occurs followed by applying at least one intermediate coating over the primer coating and then again heating the part. Finally, the method includes applying an optional top coating to the at least one intermediate coating with its appropriate process.